Average Shape Standard Atlas for the AdultDrosophila Ventral Nerve Cord

摘要

Neuroanatomy benefits from quantification of neuralstructures, i.e., neurons, circuits, and brain parts, withina common reference system. Recent improvements inimaging techniques and increased computational powerhave made the creation of Web-based databases possi-ble, which serve as common platforms for incorporatinganatomical data. This study establishes a standard aver-age shape atlas for the ventral nerve cord (VNC) ofDrosophila melanogaster. This atlas allows for the regis-tration of morphological, developmental, and geneticdata into one quantitative 3D reference system. Thestandard is based on an average adult Drosophila VNCneuropil as labeled in 24 whole-mount preparationswith the commercially available antibody (nc82) recog-nizing the Drosophila Bruchpilot protein (Brp). For thestandardization procedure no expert knowledge of brainanatomy is required and global thresholding as well asstraightforward affine and elastic registration procedures minimize user interactions. Successful registra-tion is demonstrated for tracts and commissures, geneexpression patterns, and geometric reconstructions ofindividual neurons. Any structure that is counterstainedwith anti-Brp can be registered into the standard, allow-ing for fast comparison of data from different experi-ments and different laboratories. In addition, standardtransformations can be applied to gray scale imagedata, so that any confocal image stack that is colabeledwith anti-Brp can be analyzed within standardized 3Dreference coordinates. This allows for the creation ofputative neural connectivity maps and the comparisonof expression patterns derived from different prepara-tions. The standard and protocols for histological meth-ods, segmentation, and registration procedures will bemade available on the Web.